Abstract The use of agroindustrial residues is an economical solution to industrial biotechnology. Coffee husk and pulp are abounding residues from coffee industry which can be used as substrates in solid state fermentation process, thus allowing a liberation and increase in the phenolic compound content with high added value. By employing statistical design, initial moisture content, pH value in the medium, and the incubation temperature were evaluated, in order to increase the polyphenol content in a process of solid state fermentation by Penicillium purpurogenum. The main phenolic compounds identified through HPLC in fermented coffee residue were chlorogenic acid, caffeic acid, and rutin. Data obtained through HPLC with the radical absorbance capacity assay suggest the fermented coffee husk and pulp extracts potential as a source of phenolic acids and flavonoids. Results showed good perspectives when using P. purpurogenum strain to enhance the liberation of phenolic compounds in coffee residues.

Resumo Este trabalho teve como objetivo a recuperação de compostos fenólicos a partir de resíduos da indústria cafeeira e a avaliação de sua capacidade antioxidante. Os resíduos (casca, polpa e borra de café) foram obtidos de diferentes etapas do processamento industrial do café. Os extratos fenólicos foram obtidos usando-se uma mistura de acetona e água. O teor de compostos fenólicos variou entre 72,88 e 159,50 mg AG g–1 resíduo. Mediante cromatografia líquida de alta eficiência foi detectado e quantificado o ácido clorogênico na casca e na polpa de café. Foi avaliada a capacidade antioxidante dos extratos fenólicos, verificando-se sua capacidade sequestrante de radicais DPPH e sua ação redutora sobre radicais peroxila. O resíduo com maior capacidade antioxidante foi a casca de café. Esses resultados sugerem a possibilidade de reutilização dos resíduos da indústria do café para a obtenção de compostos antioxidantes, pois tais compostos têm inúmeras aplicações nas áreas de alimentos, cosméticos e farmacêutica.

Summary The aim of this study was to recover the phenolic compounds from coffee industry residues and evaluate their antioxidant capacity. The residues (husk, pulp and spent coffee) were obtained from different steps of the industrial processing of coffee. The phenolic extracts were obtained using a mixture of acetone and water and the phenolic compound contents ranged between 72.88 and 159.50 mg GA g–1 residue. Chlorogenic acid was detected and quantified in the coffee husk and pulp by high performance liquid chromatography (HPLC). The antioxidant capacity of the phenolic extracts was evaluated and they showed DPPH radical scavenging ability and reducing action against peroxyl radicals. The residue with the highest antioxidant capacity was the coffee husk. The results suggest the possibility of reusing the coffee industry residues to obtain antioxidant compounds, since these compounds have numerous applications in the food, cosmetic and pharmaceutical industries.

El propóleo un producto natural elaborado por las abejas melíferas (Apis mellifera) a partir de los brotes y exudados de diferentes plantas, se ha empleado en la medicina tradicional desde tiempos ancestrales, debido a sus propiedades biológicas. La composición química de este producto de la colmena es altamente compleja y dependiente de la vegetación circundante al sitio de recolección. En este trabajo, se evaluaron las características fisicoquímicas, y la actividad antifúngica y antibacteriana del propóleo colectado en el municipio de La Unión (Antioquia, Colombia). Los resultados del análisis fisicoquímico del propóleo fueron: punto de fusión, 67-68 °C; sustancias extractables con hexano, 74,32 ± 0,90%; resinas solubles en etanol, 14,08 ± 2,24%; residuos insolubles, 10,47 ± 0,84%; pérdidas por calentamiento, 1,82 ± 0,32%; cenizas, 0,16 ± 0,01%, y el índice de oxidación, 8,0 ± 3,0 s. Las evaluaciones de actividad antifúngica, contra los hongos Colletotrichum gloeosporioides, C. acutatum, Aspergillus sp. y Penicillium sp., y de actividad antibacteriana, contra Bacillus subtilis (esporulada), Escherichia coli, Staphylococcus aureus y Salmonella tiphy, demuestran un efecto moderado del propóleo en la inhibición del crecimiento del microorganismo. El análisis mediante cromatografía de gases-espectrometría de masas (CG-EM), permitió la detección de ácidos grasos y sus ésteres, esteroides, triterpenos y diterpenos.

Propolis, a natural product collected by honeybees (Apis mellifera) from certain plant resins, has been used in folk medicine since ancient times, due to its many biological properties. The chemical composition of this hive product is very complex and depends upon the vegetation of the area from where it was collected. In this work, physicochemical characteristics, and antifungal and antibacterial activity of propolis collected in the municipality of La Unión (Antioquia, Colombia) were evaluated. Results of the physicochemical analysis of propolis were: melting point 67-68°C; hexane extractable substances 74.32 ± 0.90%; resins soluble in ethanol 14.08 ± 2.24%; insoluble residues 10.47 ± 0.84%; loss by heating 1.82 ± 0.32%; ash 0.16 ± 0.01%, and oxidation index 8.0 ± 3.0 s. Evaluations of antifungal activity, against the fungi Colletotrichum gloeosporioides, C. acutatum, Aspergillus sp., and Penicillium sp., and antibacterial activity, against Bacillus subtilis (sporulated), Escherichia coli, Staphylococcus aureus and Salmonella tiphy, demonstrated an moderated effect of propolis in the growth of the different microorganisms. The analysis using gas chromatography-mass spectrometry (GC-MS) allows the detection mainly of fatty acids and their esters, steroids, triterpenes, and diterpenes.